Classical chemical sciences
Phosphonic acids are effective chelating agents. They bind strongly to metal ions. Phosphonic acids have also been widely used as corrosion inhibitors along with various metal ions as Zn2+. The corrosion of various metals such as mild steel, copper, and aluminium have been prevented by phosphonic acids. Phosphonic acids exhibit good corrosion inhibition efficiency in acid medium, alkaline medium, and neutral medium. They can be used along with other inhibitors such as calcium gluconate, sodium molybdate, and trisodium citrate. Phosphonic acids show synergistic effects with these inhibitors. Various surface analysis techniques such as FTIR spectra, SEM, AFM, and EDAX have been used to analyze the nature of protective film formed on metal surface. Usually, the protective film consists of Fe2+- phosphonic acid complex along with Zn(OH)2 if Zn2+ is used. When phosphonic acids are used to prevent corrosion of iron, the adsorption process obeys Langmuir adsorption isotherm.
Keywords: Corrosion inhibition, metals, surface analysis, AFM, SEM, adsorption isotherm
Materials and environmental chemistry
The present study put an emphasis on the handling of mercury waste by using modified chitosan which obtained from shrimp shell as waste of frozen shrimp. The main aim of the study was to find out the effectiveness of cysteine as modifier to chitosan and its application for adsorption of mercury metal at water bodies. The characterisation study of adsorbent, chitosan-cysteine was done using FT-IR and SEM-EDX, wheres maximum adsorption limit was determined by AAS. The effects of parameters like pH, contact time, maximum adsoption capacity was studied at isothermal condition, on the adsorption process under study. Mechanism of adsorption process was studied according to adsoption kinetic model based under pseudo-first order and pseudo-second order, wheres adsorption isothermal was determined based on Langmuir and Freundlich isotherms. The results of the study indicate that the increase of cysteine amount in the synthetic process has no significant effect on the acquisition of % yield. Adsorption of synthetic results were determined with FTIR, SEMEDX. The optimum condition of metal ion Hg (II) adsorption by chitosan-cysteine at pH 5.5 with time of adsorption four hours. Kinetics model of adsorption follows pseudo-second order. Data on isothermal adsorption follows Langmuir isothermal model with maximum adsorption capacity to metal ion Hg (II) is 4.99 mmol/g, higher than that of earlier results that is 2.41 m mol g-1.
Keywords: Chitosan, Cysteine, Mercury, Adsorption, Langmuir isothermal, Freundlich isotherms
Mixed solid state / solution phase routes were applied to synthesize a new family of fluoride-free synthetic clays for water remediation applications. The selected samples of synthetic fluoride-free–Na-4-micas had the general formula of Na4Mg6M4Si4O22·nH2O, where M = Al3+, Bi3+, and Cr3+. Structural and micro-structural properties were determined by using both XRD and SEM. Determining the grain size of the mica, bulk was found to be in the range of 2.37–3.43 μm, which was lower than those reported in the literature. Electrical property investigation proved that Al-clay and Bi-clay exhibited semi-conducting behaviour, but Cr-clay exhibited insulating behaviour. This latter confirmed that the energy gap ΔEg was the largest for the chromium clay.
Keywords: synthesis; Mica clay; fluoride free; XRD; SEM; electrical properties.
Soil is basic means of agricultural production and subsequently the source of food for human population. Soil degradation and contamination is concerned of an issue worldwide. Several remediation techniques have been developed and applied to restore contaminated land and to keep soil properties on the sufficient level for the food production. Success of designed procedure is affected by metal presence and level of contamination. In experiments to extract metals from moderately and heavily metal-contaminated sites were investigated along with procedure to study the influence of organic fertilizers application on biomass production and a heavy metal uptake as well. The ability to accumulate risk elements in plant tissues has been proved, cadmium showed the best performance. Furthermore, a significant influence of biomass production on the total uptake of risk elements was proved. Organic fertilization had an adverse effect on the metal uptake. Extremely contaminated soils cannot directly be remediated by plants itself; they mainly need sufficient chemostabilization treatment before planting of trees.
Keywords: cadmium, lead, phytoremediation, poplar, soil, willow
Biochemistry, molecular biology and biotechnology
Sour cherry (Prunus cerasus) is a widely favored fruit worldwide. Sporadic studies were done to determine the metal ion content of this fruit. Nevertheless its effect on metal ion homeostasis has not been examined so far therefore, experiments on animal (Wistar rats) were carried out to determine the changes of metal homeostasis in liver by the effect of this fruit. Wistar rats were divided into four groups: 1. control animal with normal diet; 2. hyperlipidemic rats were fed with fat-rich diet (chow contained plus 2% cholesterol, 0.5% cholic acid and 20% sunflower oil); 3. rats were fed with normal diet + lyophilized sour cherry (0.75 g daily ad libitum); 4. rats were fed with fat-rich diet and lyophilized sour cherry. The experiment was terminated after 10 days. From the sample handed rat liver homogenate metal ion content was determined by inductively plasma optical emission spectrometry (ICP-OES). Liver fragments were fixed in 4% neutral buffered formalin, embedded in paraffin, and 5 micrometer sections were cut and stained with hematoxylin–eosin. As a result of our experiment the concentration of metal elements were found to decrease significantly in the hyperlipidemic animals fed with sour cherry (Újfehértói fürtös), although there wasn’t any significant change in result between the 1. (control animal with normal diet) and the 3. (rats were fed with normal diet + lyophilized sour cherry) group. On the basis of histological study it was established that the treatment with Fanal was the best, although Pipacs and Újfehértói fürtös were also significant in liver regression of hyperlipidemic animals with fatty liver, therefore it is concluded, that sour cherry treatment is beneficial to lower the hyperlipidemy and fatty degeneration.
Keywords: sour cherry, metal elements, hyperlipidemy
In the present study the contents of Cu, Mn and Zn were investigated in the grains of winter wheat (Triticum aestivum L.). Plant samples were collected of the year 2004 when the weather conditions were very humid and wet. Samples were harvested and collected from five experimental stations of the Hungarian national long-term fertilization trials. These stations are as follows: Bicsérd, Iregszemcse, Karcag, Nagyhörcsök and Putnok. These experimental fields have different types of soil and climatic conditions. The elements content of samples were measured using inductively coupled plasma optical emission spectrometer (ICP-OES) and inductively coupled mass spectrometer (ICP-MS) followed by digestion with HNO3-H2O2 solution. Data analysis was done using SPSS for Windows 13.0 Software package. All data were subjected to ANOVA method, but after detection of significant differences (P<0,05) data were subjected to Duncan’s test to allow separation of means. The results of studies proved that the different regions caused significant (P <0.01) difference in the element content of winter wheat samples.
Keywords: Copper; Manganese; Zinc; Mass spectrometry; Environmental chemistry
The present study aimed to investigate the macro- and the microscopic structure of femoral bone tissue in adult male rats after selenium (Se) and simultaneous exposure to Se and Diazinon (DZN). One month-old male, Wistar rats were randomly divided into three groups, of 10 males each. In the first group (EG1), rats were administered by Se at a dose of 5 mg of Na2SeO3/l in drinking water for 90 days. In the second group (EG2), animals received a drinking water containing 5 mg of Na2SeO3/l and 40 mg of DZN/l for the same time period. The third group of males without Se and DZN administration served as a control group (CG). Our results revealed a significant decrease in femoral length and cortical bone thickness in experimental groups (EG1, EG2) of rats compared to the control ones (CG). Rats from experimental groups (EG1, EG2) also displayed different microstructure in the middle part of the femur, where vascular canals expanded into central area of the bone while, in control rats, these occurred near endosteal surfaces only. Additionally, a smaller number of primary and secondary osteons was identified in experimental groups of these rats. A few resorption lacunae were observed in them simultaneously administered to Se and DZN. Based on these findings we can conclude that sub-chronic exposure to Se and simultaneous exposure to Se and DZN influences significantly macro- and microscopic structure of femoral bone tissue in adult male rats.
Keywords: femoral bone, macroscopic analysis, histomorphometry, rat, selenium, diazinon
Trace elements play an important role in human health. Some trace elements are essential, but some are harmful – especially in higher concentrations. Aluminum is not considered as an essential element for human beings, but has, in contrary, been correlated with various human pathologies for example Dementia, Parkinson and Alzheimer disease. Its uptake is mainly via food products for example tea, in the form of a food additive or via coming in contact with aluminium containing devices used during food processing and storage. The permissible daily dose for an adult is 60 mg of aluminium. Although no limit concentration for aluminium is given in the Codex Alimentarius Austriacus, the determination of the aluminium content in food and beverages is of great concern. In this study, different kinds of tea (black tea, green tea, fruit tea and herbal tea) were analyzed for their aluminium contents. The powders were brought into solution with a microwave assisted digestion unit at temperatures up to 220°C with diluted nitric acid as digestion medium. Furthermore, the aluminium concentrations have been determined in freshly prepared tea infusions in order to examine the extractable amount. The aluminium content in all solutions has been determined with ICP-OES (inductively coupled plasma-optical emission spectroscopy). Statistically significant differences between the different kinds of tea could be found, whereas the real tea types (green and black tea) contain more aluminium than fruit or herbal teas. The mean values of total concentrations of aluminium found were (0.91 ± 0.31) g/kg for green tea, (0.76 ± 0.38) g/kg for black tea, (0.23 ± 0.09) g/kg for herbal tea and (0.22 ± 0.08) g/kg for fruit tea. For the tea infusions (4.33 ± 0.35) mg/L for green tea, 4.40 mg/L for black tea, 0.52 mg/L for herbal tea and (0.12 ± 0.02) mg/L for fruit tea. These results are in good agreement with literature data.
Keywords: herbal tea, black tea, green tea, fruit tea, aluminium.
Cobalt (Co) is an essential trace element for mammals required for the synthesis of vitamin B12. When cobalt was applied chronically it tends to accumulate in different organs and tissues that can induce pathological alterations. We focused our present study on the comparative effects of chronic exposure to cobalt chloride (CoCl2·6H2O) or cobalt EDTA (Co-EDTA) on testis and sperm count in mice of different ages. Both compounds were given in drinking water water with doses per day of 75 mg/ kg or 125 mg/ kg, respectively. Treated animals were sacrificed at different time intervals (on days 18, 25, 45 and 60). The most obvious changes in testis morphology - depletion and retardations in germ cell development, disorganization of seminiferous epithelium and SCO (Sertoli-cell-only) tubules were observed on the studies of 45 and 60 days respectively. In early puberty, testis weight was reduced in similar extend (with 25%) after high doses of both Co compounds whereas in early maturity and adulthood this parameter was reduced significantly and more severe after exposure to high dose CoCl2 as compared to Co-EDTA, probably due to the stability of the complex Co-EDTA and its weaker absorption. Concerning gonado-somatic index and sperm count in mature animals we found similar tendency of more adverse effects with high dose of CoCl2. As a result of our work and data in literature we can conclude that the effects of chronic exposure to cobalt depend of the type of the compound used, dose, level, time duration as well as on the age of the animals under experiment. Cobalt could be considered as a possible risk factor for male fertility and health.
Keywords: Cobalt chloride, Cobalt-EDTA, in vivo model, mouse testis, sperm count
Industrial and engineering chemistry
The utilization of wax phase change materials (WPCMs) as raw material has been reviewed in the present article. Additional use of WPCMs into the solar energy system, the construction system, the air conditioning system and the textiles products has also been discussed. The melting point, fusion heat and the properties of commercial WPCMs have also been compared. The complete utilization of WPCMs has been resulted in good economical and social benefits.
Keywords: review; wax; phase change; materials; utilization